1. Field of the Invention
The present invention relates to a lamp base structure of a series of Christmas lamps, especially to a lamp base the outer conducting piece of which has a preferred water-proof effect.
2. Description of the Prior Art
In the prior lamp base structure of a series of Christmas lamps, metal conducting pieces (positive and negative) are engaged on the center of the seat and the peripheral wall of the lamp base. As the lamp is engaged on a predetermined position of the lamp base, those metal conducting pieces come into contact with predetermined positions of the lamp base, thus the weight of the lamp is reduced.
However, the outer conducting piece engaged on the inner peripheral wall of the lamp base has a plate shape. Therefore, as the conducting piece is engaged in the engaging hole of the peripheral wall of the lamp base, the gap between the conducting pieces and the outer periphery of the lamp base is smaller, approximately 1 mm. If the prior lamp base structure is used as a water-proof structure, it is probable that the water may enter into the lamp from the outer periphery of the lamp base, thus it will not conform with the security standard of U.S. UL 588.